Chapter 36, Problem 1DQ

To determine

Why sound waves and water waves undergo diffraction easily than light waves.

Answer to Problem 1DQ

As the wavelength of the light wave is smaller than sound waves, the hole size or slit size should be very small for diffraction to happen. It is difficult to create such small slits. So diffraction of light is difficult to observe.

Explanation of Solution

Sound waves and water waves have wavelengths in the order of one meter. The common condition for diffraction to occur is that the size of the slit or hole must be less than the wavelength of the incident light. Holes in the range of one meter can created easily.

Light waves have wave lengths in the range of few micrometers. Hence according to the condition of diffraction the size of the slit or diffraction hole must be less than this micrometer wavelength. It is very difficult to create holes having size in the range of micrometers.

Thus the difference in wavelength between light waves and sound waves is the reason for slow occurrence of diffraction in light waves.

Conclusion:

As the wavelength of the light wave is smaller than sound waves the hole size or slit size should be very small for diffraction to happen. It is difficult to create such small slits. So diffraction of light is difficult to observe.